Lee Catchment Flood Risk Assessment & Management Study


Client: Office of Public Works
Location: Cork, Ireland
Value: €1.2 Million (Engineering Services)
Scope: Hydrological Analysis; Hydraulic analysis, modelling and flood mapping; Flood defence asset condition and performance appraisal; Strategic Environmental Assessment



The Lee CFRAMS is the pilot CFRAMS for Ireland, which required extensive hydrological analysis and hydraulic modelling of the River Lee, its tributaries and Cork Harbour (225 km of river model length) in order to identify and map the flood risk in the catchment and inform the flood management options. The project makes use of a large range of data provided by a number of stakeholders including local authorities, public agencies and national government departments. The project team have built up a knowledge of and good relationship with the key stakeholders and data providers.

The hydrological assessment of the Lee catchment statistically analysed records from 41 meteorological and 21 hydrometric stations, combining both Flood Studies Report (FSR) and UK Flood Estimate Handbook (FEH) techniques. By using both FEH pooling group and donor catchment approaches, all flow estimates, including ungauged catchments were directly based actual flood behaviour within the study catchment.

The hydraulic analysis for Lee CFRAM involved developing river models for 225km length of river (eight separate models) using hydraulic modelling software ISIS 1D and ISIS 2D. More detailed ISIS 2D modelling approach was used in the dense urban area of Cork City and Cork Harbour. The models were used to produce flood extent, hazard and risk maps which provided a basis for selecting a number of different options for managing the flood risk in the catchment. Based on the results of the above analysis, a Catchment Flood Risk Management Plan (CFRMP) was developed.

As part of the development of the Lee CFRMP, we also undertook the Strategic Environmental Assessment (SEA). The SEA intended to ensure that the recommendations of the final plan were environmentally appropriate and that opportunities for environmental enhancement, ‘soft’ solutions and shared benefits were fully realised.

The SEA Environmental Scoping Report for the Lee CFRAM was published in April 2007 to inform consultation on key catchment issues and the development of Environmental Objectives. More information on Lee CFRAMS is available at